PC crashes when playing high spec games

my pc keeps crashing when I play high end games only when I play high end games it will crash low spec games is fine and any other time its fine, it gose black screen and then restarts and some times it just gose black screen and I have to press the power button again to turn it off and back on I dont no what the problem is iv got all the drivers up to date checked for viruses checked registry put new paste on the CPU as it was running hotter then it should fort that would of fixed it but nothing tried using another PC tower still nothing I been using speccy to check how hot everything is and its fine just turns off cant find the problem, help would be really appreciated

I would say update drivers. But they may not help either. Sounds more like the card could be bad. Are you able to switch out another card. If so and everything works fine. I would say the main card is faulty. Check the software for your card, It also maybe just a few setting that need changed. I am sure someone here may be able to assist you . With some other ideals. To help

Did a quick search on Winpower, unfortunately I didn't find many positive comments. Might be GPU issue, but looks like it could also be a PSU issue where it's not supply enough to the graphics card. Is there another PSU you can borrow?

no I dont have another PSU but its looking like I mite have to take a trip down to the computer shop to get another one looking on the side of my PSU from 1 +12V its giving out 34A and my gfx card minimum is 42amps but iv got a 6 pin PCI connector and 2 Molexes (I think thats what there called) plugged into the 8pin PCI adapter so surely them 2 together are giving out enough amps RIGHT????

Ye defo looking like it could be the PSU I use a program called precisionX and under clocked the gfx card and set all the games to low spec and it don't crash ardly, just saving for a better power supply I was looking at a...